In one form of known electrochemical cell for use as a primary battery, aqueous electrolyte is flowed between a reactive metal anode and an air cathode. The anode is conventionally formed of a chemically and electrochemically reactive metal, such as lithium and sodium. Illustratively, such electrochemical cells are disclosed in U.S. Pat. Nos. 3,791,871 of Leroy S. Rowley, 4,001,043 of William R. Momyer, and 4,269,907 of William R. Momyer, et al, disclosures of which are hereby incorporated by reference.
It has been found that air cathode structures, such as those developed for fuel cells, are not adaptable for use in such electrochemical cells as they have been found to have insufficient durability to withstand degradation by the electrolyte flowing across the electrolyte face of the cathode element, and the pressure imbalances which are present at the cathode structure during discharge of the electrochemical cell.
Illustratively, in U.S. Pat. No. 4,364,805 of Douglas K. Rogers, an air cathode is disclosed utilizing air blow-through at pressures in the range of 2 to 15 psig.
In U.S. Pat. No. 4,269,907 of William R. Momyer et al, an electrochemical cell is disclosed wherein the reactive metal anode is separated from the cathode by a nonconductive flow screen.
In U.S. Pat. No. 3,438,815 of Jose D. Giner, an electrochemical device is disclosed wherein at least one of the anode and cathode comprises an integral porous metal layer in physical contact with a separate catalytic layer. The integral porous metal layer is in contact with the electrolyte of the cell in operation thereof.
In the above indicated U.S. Pat. No. 4,269,907 of William R. Momyer et al, a nonconductive element is disposed between the anode and cathode to maintain proper spacing therebetween.